The gravitational slingshot is a way that scientists have truly harnessed the gravitational pull of a planet by using it to launch satellites and other useful projectiles towards their desired locations. This method was developed through the use of Newton's Laws of Gravity and Kepler's Laws of Planetary Motion. When these ideas of gravity and the shape of a planet's orbit were brought together piece by piece, this new theory changed how a projectile traveling through space could simply cross an orbital pattern, which would in turn change the path of the moving object. The change in the path accelerates the object at a higher rate and sends it speeding off in its proper direction. The gravitational slingshot doesn't guarantee perfect results every time, but it has shown to be an extremely helpful technique in the world of space travel, which when studied and tested can be further improved to ensure safe and accurate results every time.[1]
Newton, while sitting out in a field one day, was hit on the head by an apple that fell from a tree. Most people would think nothing of this event, but Newton brought into perspective that some force had to draw that apple to ground once it was released from the branches of the tree. Through much observation and testing, Newton came up with a name for this force. He called it gravity. Newton created three laws to use as guidelines for gravity. Law one states that an object in motion stays in motion and that an object at rest stays at rest. The second Law states that force equals the product of mass and acceleration. The final Law simply states that for every action, there is an opposite and equal reaction. These theories originated from something as simple as Newton observing how one object reacts to another with the presence of gravity. Using these laws, scientists have been able to formulate ways to make travel in space more successful and efficient. [2]
Kepler established the Laws of Planetary Motion. The first Law states that the orbit of every planet is an ellipse with the Sun at one of the two foci. The second law states that a line joining a planet and the Sun sweeps out equal areas during equal intervals of time. And the final Law tells that the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. Kepler's Laws also come into play with the use of the gravitational slingshot, because Kepler believed that the orbit that a planet takes around another body follows an elliptical pattern, instead of traveling in a perfect circle. Of course each planet has a specific elliptical orbit, just as humans have different fingerprints to identify them. Before launching their equipment into space, each planet must have its pattern identified to ensure accurate results for the launch. This knowledge helps scientists identify where the ellipses are in relation to the paths of orbit so that they can launch satellites in the proper direct, at the proper time, with the proper velocity. Combining both of these sets of theories together has lead the way to the effect we know as the gravitational slingshot effect. [3]
Today's Use
Today, the gravity assist effect is used extremely often by NASA and the Air Force. It is the most fuel efficient, naturally occurring “booster” in the universe. The gravitational force of a planet, even one as small as Mars, cause exponentially increase the velocity of an object. Using the Conservation of Kinetic Energy equation, which was developed by Newton, we see that no kinetic energy, or displacement energy is being lost as Gravitational Potential Energy. GPE is just that, potential energy that is not put into motion quite yet. In addition to Kinetic Energy, Linear Momentum is conserved also. The Conservation of Linear Momentum Equation proves that no speed is lost in the use of a gravity assist. In fact, it is greatly increased. Both of those equations, when combined, lead back to Newton’s Law of Collisions, proving that this method of acceleration is accurately accredited to Sir Isaac Newton himself.
When the probe or satellite, or even the space ship is slung around the planet, it not only keeps its own speed, proved above, but it also inherits twice the velocity of the planet itself. As the planet rotates, it also revolves around the Sun. If the rotating field is hit at the right time and at the right angle, all of the velocities of all parties involved are summed up in one final velocity of the probe that is massively superior to its initial speed. The probe’s velocity is perpendicular to the planet’s gravitational field and ends up facing in the exact opposite direction it started in, but infinitely faster. Infinitely because theoretically, it can be used with any spectral body of any size. All of this is accomplished with a tedious calculation and just enough fuel to launch the probe with the right speed and direction at the right time, saving not only money, but natural resources.[4]
Advantages
Normally, it would take almost twenty-four years to get from the Earth to Pluto. That’s travelling at about 17,000 mph. With the use of the gravitational slingshot around as many planets as possible, that time could be cut in half and that speed could be increased by upwards of 5000%. For instance, the New Horizon’s craft is using only the gravitational assist from Jupiter and is managing speeds of over 32,000 mph. If we used the full potential of something as large as the sun, that speed could be increased to over 1.1 million mph. There are comets that do it, so there is nothing that could stop a shuttle from doing the same thing. It is the only way humanly possible to travel even remotely that fast at a constant rate, let alone instantaneously. Light itself travels at 186,287 mph. Using the Sun’s gravitational field, we could travel ten times faster than light. Light years would no longer be a barrier. Exploration could be infinite.[5]
Courtesy of Student Web
The development of this method of assisted travel is has a potential we have not even begun to uncover. The possibilities are endless, the explorations are innumerable, and the discoveries are universal. Without the use of this theory, any space travel farther than Mars or Venus would be an unthinkably daunting task. Thank you, physics.
Presentation
Sometimes Hollywood Gets It Right
The plan to save the Apollo 13 astronauts was completely plausible. This scene practically explains the entire concept of gravity assist, or gravitational slingshot, all on its own. It is the perfect example in a somewhat modern day scenario that illustrates exactly what this assist is used for, and how it is an advantage for NASA and their affiliates.
Experiment
There are numerous ways that one could choose to demonstrate just how the slingshot effect works. The hypothesis reached was that an object that is assisted with the gravitational slingshot will change direction and speed. The purpose of the following experiment is to demonstrate just how the use of an artificial slingshot affect, using a bucket as the gravitational force, can make an object in this case tennis balls, go a further distance in a different direction. To begin this experiment, the hat, which is used to catch the launched object, is spun around in an ellipse shape, and then releases the tennis balls into a new direction, changing the ball’s acceleration. In order to contrast the changes in direction, another projectile was also launched, without the use of a hat, which makes this tennis ball appear as nothing more than something that was traveling through the deep abyss of space at a constant undisturbed speed and direction. This tennis ball in space will not stop until acted upon by an outside force, as stated in Newton’s First Law of Motion. When the tennis balls were launched with no hat, it continued moving in a constant direction until reaching the ground. Using a tape measure, we found that the planet Kat and the hat will be 10 meters away from the starting point of where the tennis balls are thrown. We will time how long it takes the ball to make it 10 meters and use that to discover speed of the tennis balls. The data below is the data gathered from this experiment, which did support the hypothesis.
Data Table
SPEED OF TENNIS BALL
Trial 1
Trial 2
Trial 3
Average Speed
W/ Hat
19.8 m/s
22.7 m/s
22.3 m/s
21.6 m/s
W/O Hat
6.12 m/s
7.03 m/s
6.48 m/s
6.54 m/s
In this experiment, the hypothesis formulated was proven true. There may have been slight human error in the speed that the tennis balls were originally launched, but constant variable, such as the person launched the tennis balls, were kept the same throughout then entire experiment. Another error encountered during this experiment was the present of gravity and wind, which could have affected the accuracy of the results. Conducting an experiment like this would not have been possible without the use of previous knowledge from those before our time. This shows that taking and using this knowledge gained from different scientists and placing it together side-by-side can cause new discoveries to be made and observed. This will continue to advance knowledge in science and physics and push it in an entirely new direction. This direction is what led scientists to persevere through much experimentation, calculating, and coming to conclusions to see whether their hypothesis was correct or not. Though one’s hypothesis may not always be proven true, it leads them on a better path to find answers to the questions they still have unsolved, which can be found by testing a new hypothesis based on gathered data from the previous experiments.
Gravitational AssistTable of Contents
Introduction
The gravitational slingshot is a way that scientists have truly harnessed the gravitational pull of a planet by using it to launch satellites and other useful projectiles towards their desired locations. This method was developed through the use of Newton's Laws of Gravity and Kepler's Laws of Planetary Motion. When these ideas of gravity and the shape of a planet's orbit were brought together piece by piece, this new theory changed how a projectile traveling through space could simply cross an orbital pattern, which would in turn change the path of the moving object. The change in the path accelerates the object at a higher rate and sends it speeding off in its proper direction. The gravitational slingshot doesn't guarantee perfect results every time, but it has shown to be an extremely helpful technique in the world of space travel, which when studied and tested can be further improved to ensure safe and accurate results every time.[1]
The Men Behind the Idea
Newton
Newton, while sitting out in a field one day, was hit on the head by an apple that fell from a tree.Most people would think nothing of this event, but Newton brought into perspective that some force had to draw that apple to ground once it was released from the branches of the tree. Through much observation and testing, Newton came up with a name for this force. He called it gravity. Newton created three laws to use as guidelines for gravity. Law one states that an object in motion stays in motion and that an object at rest stays at rest. The second Law states that force equals the product of mass and acceleration. The final Law simply states that for every action, there is an opposite and equal reaction. These theories originated from something as simple as Newton observing how one object reacts to another with the presence of gravity. Using these laws, scientists have been able to formulate ways to make travel in space more successful and efficient. [2]
Kepler
Today's Use
Today, the gravity assist effect is used extremely often by NASA and the Air Force. It is the most fuel efficient, naturally occurring “booster” in the universe. The gravitational force of a planet, even one as small as Mars, cause exponentially increase the velocity of an object. Using the Conservation of Kinetic Energy equation, which was developed by Newton, we see that no kinetic energy, or displacement energy is being lost as Gravitational Potential Energy. GPE is just that, potential energy that is not put into motion quite yet. In addition to Kinetic Energy, Linear Momentum is conserved also. The Conservation of Linear Momentum Equation proves that no speed is lost in the use of a gravity assist. In fact, it is greatly increased. Both of those equations, when combined, lead back to Newton’s Law of Collisions, proving that this method of acceleration is accurately accredited to Sir Isaac Newton himself.When the probe or satellite, or even the space ship is slung around the planet, it not only keeps its own speed, proved above, but it also inherits twice the velocity of the planet itself. As the planet rotates, it also revolves around the Sun. If the rotating field is hit at the right time and at the right angle, all of the velocities of all parties involved are summed up in one final velocity of the probe that is massively superior to its initial speed. The probe’s velocity is perpendicular to the planet’s gravitational field and ends up facing in the exact opposite direction it started in, but infinitely faster. Infinitely because theoretically, it can be used with any spectral body of any size. All of this is accomplished with a tedious calculation and just enough fuel to launch the probe with the right speed and direction at the right time, saving not only
money, but natural resources.[4]
Advantages
Normally, it would take almost twenty-four years to get from the Earth to Pluto. That’s travelling at about 17,000 mph. With the use of the gravitational slingshot around as many planets as possible, that time could be cut in half and that speed could be increased by upwards of 5000%. For instance, the New Horizon’s craft is using only the gravitational assist from Jupiter and is managing speeds of over 32,000 mph. If we used the full potential of something as large as the sun, that speed could be increased to over 1.1 million mph. There are comets that do it, so there is nothing that could stop a shuttle from doing the same thing. It is the only way humanly possible to travel even remotely that fast at a constant rate, let alone instantaneously. Light itself travels at 186,287 mph. Using the Sun’s gravitational field, we could travel ten times faster than light. Light years would no longer be a barrier. Exploration could be infinite.[5]The development of this method of assisted travel is has a potential we have not even begun to uncover. The possibilities are endless, the explorations are innumerable, and the discoveries are universal. Without the use of this theory, any space travel farther than Mars or Venus would be an unthinkably daunting task. Thank you, physics.
Presentation
Sometimes Hollywood Gets It Right
The plan to save the Apollo 13 astronauts was completely plausible. This scene practically explains the entire concept of gravity assist, or gravitational slingshot, all on its own. It is the perfect example in a somewhat modern day scenario that illustrates exactly what this assist is used for, and how it is an advantage for NASA and their affiliates.
Experiment
There are numerous ways that one could choose to demonstrate just how the slingshot effect works. The hypothesis reached was that an object that is assisted with the gravitational slingshot will change direction and speed. The purpose of the following experiment is to demonstrate just how the use of an artificial slingshot affect, using a bucket as the gravitational force, can make an object in this case tennis balls, go a further distance in a different direction. To begin this experiment, the hat, which is used to catch the launched object, is spun around in an ellipse shape, and then releases the tennis balls into a new direction, changing the ball’s acceleration. In order to contrast the changes in direction, another projectile was also launched, without the use of a hat, which makes this tennis ball appear as nothing more than something that was traveling through the deep abyss of space at a constant undisturbed speed and direction. This tennis ball in space will not stop until acted upon by an outside force, as stated in Newton’s First Law of Motion. When the tennis balls were launched with no hat, it continued moving in a constant direction until reaching the ground. Using a tape measure, we found that the planet Kat and the hat will be 10 meters away from the starting point of where the tennis balls are thrown. We will time how long it takes the ball to make it 10 meters and use that to discover speed of the tennis balls. The data below is the data gathered from this experiment, which did support the hypothesis.Data Table
SPEED OF TENNIS BALLIn this experiment, the hypothesis formulated was proven true. There may have been slight human error in the speed that the tennis balls were originally launched, but constant variable, such as the person launched the tennis balls, were kept the same throughout then entire experiment. Another error encountered during this experiment was the present of gravity and wind, which could have affected the accuracy of the results. Conducting an experiment like this would not have been possible without the use of previous knowledge from those before our time. This shows that taking and using this knowledge gained from different scientists and placing it together side-by-side can cause new discoveries to be made and observed. This will continue to advance knowledge in science and physics and push it in an entirely new direction. This direction is what led scientists to persevere through much experimentation, calculating, and coming to conclusions to see whether their hypothesis was correct or not. Though one’s hypothesis may not always be proven true, it leads them on a better path to find answers to the questions they still have unsolved, which can be found by testing a new hypothesis based on gathered data from the previous experiments.
References